Why does he want us at his probaton violation hearing so bad?

My friend (ex boyfriend) is in jail for hitting a woman. I have also become good friends with his current girlfriend (whom he also beat up in the past and was arrested for) of 5 years. Ok long story short he wants us to help him get clothes, money, prepare for his court hearing next week. He has been in jail since March. his CURRENT girl is doing everything he wants and wants to help his case by providing some evidence at his hearing that the girl accusing him is crazy. I disagree and think he belongs locked up a few years. I help HER as my friend but I wont go to his hearing. She is getting mad at me saying " we are all he has and I promised to be there. Now I don't have a ride" and crap like that. Also he is telling her I PROMISED to be there for him too and bring her WITH me to his hearing. I never did say that. WHY is he so insistent that we be there? I wouldn't lie for him (altho she would) and I DOUBT we will make a difference anyway !